Letter: Genome mysteries

Sir: The completion of the human genome project will certainly be a major technical achievement, but I am puzzled.

Humans are not clones, and each of us differs genetically from our neighbours, by as much as 3 million letters of the genetic code, according to a recent report. So whom exactly will the deciphered "standard" genetic code represent? A black, brown-eyed Egyptian with an unrecognised predisposition to nailbiting and car-sickness? A blond blue-eyed Chinese subject to early balding? How does the project cope with all the potential variations?

K W JOY

Kenilworth, Warwickshire